Precast concrete joist and slab construction



June 18, 1935. H, o. KLoTz 2,004,991 I PRECAST CONCRETE-JOIST AND SLAB CONSTRUCTION I v Filed sept. 22, 1954 www A TTORNE YS.

Patented June 18, l1935 2,004992 PRECASTLCONCRETE .JOST AND SLAB,

f CONSTRUCTION Henry 0.I Klotz,:Betl1el,' Conn., assignor to Thef Redding1-Marble Company, New Haven, Conn., acorporation ofUonnecticut Application September 22, 1934, Serial No. 745,079

.iofolaima (o1. vee-68) t This invention. relates to newY and useful irnto the present invention precastireenforced "conf-f` provement-s in building yconstruction andhas parcrete joists I are used to. supportk precastreii ti'cular relation to a precastaconcretemjoist` and enforced concrete slabs I I Jsotliat no forms ortheslab`construction. like are required ,atjthepoint'ofconstructionof 5' An object of the inventionis toprovide an inie a building, all :of `th e ioists and slabs having'beenM 5" proved 'precast 'concrete joist and slab' construccast ina shop. As here disclosed', the slabs Itard" tion. forthe floors or roofs of buildingsyandwhich castzof concrete vor similar material suitably construction may be used to rapidly and econemenforced and are of a Width` Correspending.@Witlof ',v y ically set unthe iloors and roofs of buildings, dothe spacing of'wooden sleepers,I2'to1vvhichthe 10" ing `away with the .necessity of setting up forms wooden ilooring` I3 is nailed. Thev lengthoithe l0 and pouring the concrete. on the job and permitslabs is such that when the center of "aslab'is. oni;- ting` the Aprecasting of the jo'ists and the :door or` one joistthe respective endsofH thatslab"lrestfoii;l roof construction in a shop, and'then assem-A the adjacent joists to the righty and'l eftf of"thfe'Vv t blingon the job. v rstmentioned joist. Further, the'slabs are ar'- l5' Other. objects'and .advantages will'become ap-I ranged in staggered relation softhatthetransL 1.5"

parent` from a consideration of the following deverse joints in a. fioor'or roof' construction'pdo not' tailed jdescription taken in connection with the align and this is fully illustrated in Fig. l1 'where-'f accompanyingr drawing whereinv a. satisfactory in the joints atv the Atransverse ends ofthe slabfA, y embodiment'ofv the invention is'A shown. Howare designated `I4"arid I5While. the jointatone:

" ever, it will be understood Sthatthe invention is l transverse end of the slab B is shown atil. '2v` notlimited to the details disclosed but'includes As shown, thejoists IU are inrthe formjovfll1``- alllsuch' variationsand modifications as lfall vvith-` beams cast from concrete'and each joist includes, in thespirit of theinvention andrthescopepf lower` and upper longitudinally extendinggreen" th'e. appended claims., forcing yrods I'I and I8 'Land they, may rvlo'etiedtor- Inthedrawing:`' 4 ,s

Fig...1.is.a,plan.view 'ofja po-rtionfofa flooremded in and extending ,above theupperjsides or' bDdYiIlg.v the.. invention, aA partfof' the jwooden the joist' arestirrups .I9 and suchsti'rrupsfar'e' iioringrbeing. .omitted';. f anchored inthe respective jois'ts, "as forexarnple geth'er'in any suitable manner. Partially emloed-4 25` `r .Figizisasectionai viewthereon'theviewsbeing, and; preferably by having.their.,mwen-ende "takenlsubstantia1lyfalong,,theplanepof`,theline formed into eyes 20 wrappedabcut thelower 30- 2 '2"of Fig. 1; l Y reenforcing bar andfalsoby,being'bentflaterally: Fig..3.isa..detail sectional.view,v onanlenlarged around. and. .spot .welded vto theupperfreenforce' sca1ethe view. beingztakemsubstantially.along ing bar I8 as at 2I. Itfwill thus be seen that:

, theplane .ofthe lline 3T3 .of.,Fig,. 1; these stirrups provide means'for tying there- Fig..4 isan enlargeddetail sectionalviewftaken enforcingv rods ITI and I8f` together"rnaking-`a- 3'5" substantiallyalongthe planeof .the ,line 41-4 ofY strong. rigid and unitary construction, additional@ Eig..1; tying means vmay be providedbetween ".thestir'-v4 Fig. 5.is.an enlarged sectionalviewf ytaken sub.-y rupsif their spacingis too4 great or ifjadditional' `stantiallyialong.the-plane ofthe linefS--Bl ofig.r tying' vmeans is found necessary. orjdesiralole.-

" 2,.parts.of.,the joist beingbroken away; The stirrups may `loe otherwise anchored'in thevv 46 Fig.6 is an enlargeddetal sectionalviewtaken joists if desired. llrom the"drawingjitwilliibe substantially along the. -line 6'T-6-.ofjFig. .1, and. clear that thestirrups I9 are inthe:forniA offrodsA showingthe joint at theadjacent transverse edges and `that the upper end o f eachf stirrupjis screw:

- of .apair of `rneetingfslabs threaded to receive a nut 22 belowwhich 45 Fig. Visa detaiL viewillustrating the construcbe located a Washer 35; 45

tion.oflthelongitudinal edgesofthe slabs; y The Wooden sleepers vI2Lal ove referred 'tol'are Fig..8 isfaviewsimilarftoFig. 4.but.illustratng, received'in grooves andjtoprovide suchL grooves the.inyentimwhenwooden ,nominees/not. used;` the klongitudinal edges ofthe slabs 'arerabbeted j Fig..9,.is.a.sectionalyiewillustrating.a further.. whenathe' longit dinal` edges of two slabs are" slightyariation., n placed. together asy inFig..4.the twoy rabbets i37 Inethe-drawingftheinvention sshown asused formav tapered groove v.to .receive a.V transversely, iniconstructingoftheyfloorof azbuilding-although Wedge-shapedwwooden sleeper.;I2..,.Thespaoing as shown at 23 Fig. 7 f It will be evident.that;y 56,;

5.; it will be understoodlthattit mam-also be-fused-ginv 0,5. the vstirrups l. ItLisI .such .thatfthey enterthef 51;;

constructing the roof of a building. According grooves formed by the rabbets 23and`the upper ends of the stirrups extend into the wooden sleepers I2 and the latter are counterbored as at- 24 to accommodate the nuts 22 and washers 35.

With this arrangement it will be noted that the nuts and the upper threaded ends of the stirrups are below the upper surfaces of the wooden sleepers so that the stirrups and nuts will not interfere with the laying of the wooden iiooring I3. Usually a second 'or finishing ilooring (not shown) is applied on top of the flooring I3. Preferably the sleepers extend slightly above the upper surfaces of the slabs I3 so that there will be a small space 25 below the wooden iiooring. It will be apparent that the sleepers may be drawn against the portions of the slabs forming the bottom walls of the grooves in which the sleepers are located, on tightening of the nuts 22, and that when the sleepers are clampedy against such portions of the slabs the sleepers are securely tied down making a tight closed joint between the slabs, and that the slabs themselves are tied down onto the joists.

On its under side intermediate its ends each slab is provided with a transverse, recess or groove 26 for the reception of. the upper edge of a joist and at its transverse edge portions each slab is provided with one-half of such groovevor recess as at 21. the slabs are in place the transverse joints between adjacent slabs are made up as best shownr in Fig. 6. There it will be noted that the recesses 21 in the adjacent portions of a pair of slabs form a groove receiving the upper edge of a joist I0. The transverse edges of the slabs are preferably inclined slightly providing a tapered joint which may be filled with grout as at 28 (see particularly Fig. 6).

If a cement or terrazzo floor is to be used then the arrangement is as shown in Fig. 8 where the joist I0 and the slabs II are of the construction already described. The wooden sleepers are omitted when the cement or terrazzo floor is to be used, and in place of such sleepers metal strips 29 are placed in the grooves formed between the longitudinal edges ofthe slabs, and the stirrups I9 pass through such strips whereby on tightening the nuts 22 of such stirrups the strips will be clamped against the edge portions of the slabs and the latter will be clamped to the joists. Thereafter, ythe concrete or terrazzo floor 30 may be poured on top of the slabs iilling in the grooves at the longitudinal edges thereof, or the grooves maybe nearly filled with grouting 3I prior to the pouring of the floor 30.

Fig. 9 shows a further slight variation and in this iigure a Wooden sleeper I2 is shown in place in a groove formed between the adjacent longitudinal edges of a pair of slabs I I and the wooden ooring I3 is secured to said sleeper. in Fig. 9 the joist is shown as in the form of a metal beam 32. Carried by such beam and extending through the groove and into the sleeperl `joist32.

It will now be understood' that according to the present invention thejoists and slabs are all precast so that the use of forms is not required at the construction site. When the joists are g in place the slabs are rested on the joists pref- WithV this arrangement when However,

erably in such staggered relation that the transverse edges of laterally adjacent joists do not align, and when the slabs are positioned the rabbeted longitudinal edges of the adjacent slabs form grooves extending transversely of the joists. It will also be clear that the upper ends of the stirrups carried by the joists will be extending into such grooves at the proper points, and when wooden flooring is to beleid .wooden sleepers properly drilled and counterbored for the reception of the upper ends of the stirrups and the nuts 22 are disposed inthe grooves with the stirrups extending into them.

If desired, washers 35 may be disposed about the stirrups below the nuts 22 and on tightening of the nuts the sleepers are firmly tied in place and tie the slabs to the joists. Fig. 8 clearly illustrates that when a concrete or terrazzo floor is to be laid the Wooden sleepers are omitted and the slabs are tied or clamped to the joists by the stirrups acting through metal strips 25. Fig. 9 illustrates the manner in which .the principles of the invention may be employed when a metal joist is used, and in, this figure it will be apparent that the stirrup 33 ties the Wooden sleeper I2 in place and also ties the slabs to thcvjoist. .Y The threaded stirrups in the preferred form origi-I natefrom, or that is are firmly secured to, the main reenforcement for the joists so are ilrmlyy anchored in them and form partof the reen,- forcement. The reenforced slabs are constructed in a manner to form receiving recessesat thefbot-f tom to t over the joists, and on the top, a continuous recess is formed at right angles to the joists that will allow a wooden sleeper to be bolted to the threaded stirrups castin the joists, the ad,-`

vantages being that said wooden sleeper will act as a continuous tie and separator, and function as a nailing strip to fasten nished wood flooring. Having thus set forth the nature of myy 'invention, what I claim is:

1. A roof or floor construction comprising supporting joists, precast cementitious rslabs on said joists, a pair of said slabs having theiradjacent edges rabbeted providing a, groove, stirrups4 anchored by and extending above said joists and entering said groove, a member in and extending j longitudinally of said groove, and means on saidj stirrups to clamp said member against the portions of the slabs forming the bottom of the, groove and vclamping said slab portions against.

chored by and extending above said joists `andi entering said groove,.a. wooden sleeper in and extending longitudinally of said groove, and

means `on said stirrups to clamp said wooden sleeper against the portions of the slabs forming the bottom of the groove and clamping `said slab portions against the joists.

3. A roof or iloor construction comprising sup? porting joists, cementitious slabs on Aand having edges extending transversely of said joistsfsaid slabs having their adjacent such edges rabbeted providing grooves extending transversely of said joists, stirrups anchored by and extending above said joists and entering said grooves, membersV in and extending longitudinally of said grooves,

and means on said stirrups to clamp said {members against the portions of the slabs forming the bottoms of said grooves and clamping said slab portions against the joists. v

4. A roof or floor construction comprising supporting joists, cementitious slabs on and having edges extending transversely of said joists, said slabs having their adjacent such edg-es rabbeted providing grooves extending transversely of said joists, stirrups anchored by and extending above said joists and entering said grooves, Wooden sleepers in and extending longitudinally of said grooves, an-d means on said stirrups to clamp said Wooden sleepersagainst the portions of the slabs forming the bottoms of said grooves and clamping said slab portions against the joists.

5. A roof or oor construction comprising supporting joists, cementitious slabs on and having edges extending transversely of said joists, said slabs having their adjacent such edges rabbeted providing tapered grooves extending transversely of said joists, stirrups anchored by and extending above said joists and entering said grooves, tapered Wooden sleepers in and extending longitudinally of said grooves, and means on said stirrups to clamp said sleepers against the por--AV tions of the slabs forming the bottoms of said grooves and clampingsai-d slab portions against the joists.

6. A roof or oor construction comprising cementitious supporting joists7 cementitious slabs on and having edges extending transversely of said joists, said slabshaving their such edges rabbeted providing grooves extending transversely of said joists, stirrups partially embedded in and extending above said joists and entering said grooves, members in and extending longitudinally of said grooves, and means on said stirrups yto clamp said members against the portions of the slabs forming the bottoms of said grooves and clamping said slab portions against the joists.

7. A roof or floor construction comprising reenforced cementitious supporting joists, cementitious slabs on and having edges extending transversely of sai-d joists, said slabs having their such edges rabbeted providing grooves extending transversely of said joists, stirrups partially embedded in and secured to the reenforcement of and extending above said joists and entering said grooves, members in and extending longitudinally of sai-d grooves, and means on said stirrups to clamp said members against the portions of the slabs forming the bottoms of said grooves and clamping said slab portions against the joists.

8. A roof or floor construction comprising cementitious joists having upper and lower longitudinally extending reenforcing bars, cementitious slabs on and having edges extending transversely of said j oists, said slabs having their such edges rabbeted providing grooves extending transversely of the joists, stirrups partially embedded in and extending above the joists and entering said grooves, said stirrups being bent about the lower and welded to the upper reenforcing bars of the joists, members in and extending longitudinally of said grooves, and means on said stirrups to clamp said members against the portions of the slabs forming the bottoms of said grooves and clamping said slab portions against the joists. i

9. A roof or oor construction comprising supporting joists,` cementitious slabs on said joists, a pair of said slabs having their adjacent edges rabbeted providing a groove, stirrups anchored by and exten-ding above sai-d joists and entering said groove, a Wooden sleeper in and extending longitudinally of said groove, and nuts .threaded on the upper ends of said stirrups to clamp said Wooden sleeper against th-e portions of the slabs forming the bottom of the groove and clamping sai-d slab portions against the joists.

l0. A roof or floor construction comprising supporting joists, cementitious slabs on and having transverse recesses receiving .the upper edges of sai-d joists, a pair of said slabs having their adjacent edges rabbeted providing a groove, stirrups anchored by and extending above said joists and entering said groove, a member in and extending longitudinally of said groove, and means adjustable on said stirrups to clamp said member against the portions of the slabs forming the bottom of the groove and clamping said slab portions against the joists.

HENRY O. KLOTZ. 

